Spot dyeing process and apparatus



Jan. 1, 1963 J. SHAW SPOT DYEING PROCESS AND APPARATUS Filed May 1, 1961 A ia) I 6 N kuk IN V EN TOR.

ATTORNEY hired States Patent Gfiicei 3,070,869 SPOT DYEENG FROCESS AND APPARATUS James L. haw, Greenville, S.C., assignor to United States Rubber Company, New York, N.Y., a corporacn of New Jersey Filed May 1, 1961, Ser. No. 106,956 15 Claims. (Cl. 28-1) Introduction and Brief Description This invention relates to a method and apparatus f applying substances, such as dyes, to strands, such as textile yarns, in spots randomly arranged along the length of the strand, and it is an object of this invention to provide an improved method and apparatus of this kind.

Yarns dyed by the method of this invention create a pleasing effect when used as the pile of rugs.

According to this invention, the strand to be treated should be bent upon itself and packed in a column or layer of substantial thickness. In the preferred embodiment the bent and packed strand is the crimped bundle created by a modified version of a yarn-crimping apparatus of the type shown in United States Letters Patents Nos. 2,311,174 and 2,747,233. The apparatus comprises an elongated yarn crimping chamber of the stuifer-box into which two cooperating rolls introduce yarn to bend the yarn upon itself and to compress it as it advances through the chamber under the pressure necessary to overcome the friction of the walls of the chamber on the yarn and to overcome any back pressure existing at the exit from the chamber.

When the strand leaves the chamber it is advanced while still bent and under pressure toward a member to contact a surface thereof which carries the substance to be applied to the strand. Preferably the member contacted is a rotatable generally cylindrical roll with its axis normal to the direction of the strand advance and arranged so that the force exerted on the roll by the advancing strand creates a turning moment in the roll about its axis.

Only part of each succeeding segment of the bent and packed strand can contact the roll surface, and the remainder is allowed to advance past the roll at the same time the part in contact with the surface is allowed to escape from that contact. Consequently given segments of the strand will have portions which received a transferred substance from the roll surface as well as other portions which did not. Conveniently the roll partially blocks the exit from a crimping chamber to provide a restricted passage through which the strand escapes past the roll to achieve this partial transfer as the roll rotates.

Another object of this invention is to provide a novel method for both spot dyeing and crimping a thermoplastic yarn. This object is achieved by crimping a thermoplastic yarn and applying dye thereto randomly in the manner heretofore described, and finally heating the yarn to heat set the crimp in it as well as to set the dye in the spots of dye applied to it.

For a better understanding of the nature of this invention, reference should be had to the following detailed description of specific embodiments thereof when read in conjunction with the accompanying drawing forming a part hereof wherein:

The Drawing FIG. 1 is a face view of a stuifer-box yarn crimper which is used as the yarn bending and packing apparatus;

FIG. 2 is an elevation of the right side of the lower part of the apparatus shown in FIG. 1 with the applicator added thereto;

FIG. 3 is a cross-section along the line 3-3 through FIG. 2;

FIG. 4 is a development view of the liquid supply font of the applicator, and

Detailed Description A stand 11) carries two rolls 11, 12 rotatably driven to advance the strand downwardly in FIG. 1 and into the crimping chamber. Strand 13 is compressed longitudinally by the action of rolls 11, 12; it is bent upon itself, and it is packed in the elongated crimping chamber. As best seen in FIG. 3, the crimping chamber frame has aback plate 14 and face plate 17 which are parallel to each other, and two parallel side plates 15, 16 defining crimping chamber 18 that is generally rectangular in horizontal cross-section. Crimping chambers of this type sometimes have a hinged lower section of the face plate weighted to enter the lower end of the chamber to create added resistance to passage of the strand through the elongated chamber and consequently to create added crimping pressure, but the device shown in the drawing has no such hinged section. The chamber shown is several inches long, and the friction developed at the Walls of the elongated chamber is sufi'icient to create the necessary crimping pressure. The length of the column of strand 13 in chamber 18 obviously is many times the strands thickness.

The structure thus far described is old in principle, and is substantially the same and functions in the same way as the apparatus disclosed in United States Letters Patent Nos. 2,311,174 and 2,747,233.

The treating material, which is preferably a liquid, is held in a font 19 which is shown in the development view of FIG. 4, and which is shown assembled and fixed to the back plate 14 of the crimping chamber frame in FIGS. 2 and 3. A clamp block 21) grips, and is vertically slidable on, the rail section 21 of back plate 14. The side plates 22, 23 of font 19 are riveted to the clamp 21?, and a set screw 24 passes through a threaded hole in clamp 20 to frictionally engage the back of rail section 21. To raise or lower font 19, set screw 24 is loosened, clamp 211 is slidvertically and set screw 2-:- is re-tightened to fix the applicator in its new position.

Two transversely extending and axially aligned screws 25, 2d are threaded through side plates 22, 23 of font 19 and are locked by lock nuts 3%), 31 respectively which fix the distance between the inner ends of these screws. Screws 25, 26 have sixty degree points adapted to fit loosely in conical central holes in the sides of a generally cylindrical roll 27 so that roll 27 is rotatably supported on the screws.

It will be apparent from the drawings and the descriptron thus far that the axis of roll 27 is normal to the direction of strand advance through the crimping chamber 18. Attention is directed to FIG. 2 where the radius of the outermost surface of roll 27 is shown approximately equal to the cross-sectional dimension from back plate to face plate of chamber 18. It also appears from this figure that in this embodiment the axis of roll 27 is posiroll 27 is positioned substantially tangent to the bottom.

plane of crimping chamber 18. Consequently a restricted passage, one of whose dimensions is designated by the character X in FIG. 2, is provided for escape of th strand past roll 27. The dimension X as used herein is measured on the line joining the lower rear corner 35 of face plate 17 and the axis of roll 27 and is the distance between corner 35 and the radially outermost element of the surface of roll 27. From FIG. 3 it will appear roll 27 is longer than the cross-sectional dimension of chamber 18 from side plate to side plate.

Two additional transversely extending and axially aligned screws 33, 34 are threaded through side plate 23,

Patented Jan. 1, 1963 smaeee 22 of font i9 and are locked by lock nuts 39, 4% respectively which fix the distance between the inner ends of these screws. Screws 33, 34- have sixty degree points adapted to fit loosely in conical central holes in the sides of a large transfer roll 28, so roll 28 is rotatably supported on these screws. The axis of roll 28 is parallel to the axis of roll 27, and the former is positioned to run in the liquid in font 1 9 and simultaneously to contact the outer surface of roll 27 (which is out of that liquid), so full 28 picks up liquid from the font and transfers it to roll 27. A metal supply tube 29 is provided so a flexible hose (not shown) may be connected thereto to introduce material from a supply into font 19.

The bottom of tube 29 is spaced a short distance from the bottom of the font, and therefor it-willallow liquid to accumulate in the font until the end of the tube is sealed cit. Thus tube 29 acts as a constant level device in much the same manner that a drinking fountain for poultry operates. The major supply of liquid is stored in a closed bottle (not shown), connected to the other end of the hose on tube 29. As the liquid runs out of the bottle by gravity, a vacuum is created which prevents additional liquid from leaving the bottle. This vacuum can be relieved by air bubbles entering through the bottom of the supply tube 29 when the liquid level falls beneath the level of the bottom of tube 29.

As best appears in FIGS. 2 and 3 roll 27 partially blocks the exit from crimping chamber 18. The surface of roll 27 is rotatable toward face plate 17 (counterclockwise in FIG. 2), so the strand to be treated passes through the restricted passage between corner 35 and the surface of roll 27 as :the strand escapes past the surface of that roll as it rotates.

Roll 28 is shown as a stainless steel roll with a knurled outer surface to facilitate liquid pick-up and transfer. Roll 27 has a fluted rubber cover so its outer surface has a gear toothed configuration. If desired roll 27 may be a knurled stainless steel roll similar to roll 28, or it may be covered with a porous substance such as porous rubber, wicking or the like.

Operation To operate the device, a strand 13 is crimped by being stuffed into restricted crimping chamber 18 under pressure by rolls 11 and 12, and the strand is moved through this crimping chamber and forced out the bottom as additional strand is stuffed in at the top. Strand 13 is in a randomly crimped state as it is ejected from the crimping chamber. While it is being forced out of the crimping chamber it is forced against the surface of roll 27. The pressure on strand 13 at the time it contacts roll 27 is less than that to which it was subjected in crimping chamber 18, and normal resilience of the strand causes it to open up at this point in an effort to reduce the pressure, but the strand is still under some pressure from crimping chamber 18.

Since the strand 13 is randomly crimped, randomly spaced spots of the material in font 19 are transferred from the surface of roll 27 to the strand. Because of the bent and packed condition of the strand which advances toward roll 27 in a continuous column, only part of each succeeding segment of the strand can contact the surface of roll 27. The pressure on the strand as it touches roll 27 creates a turning moment about the rolls axis due to the off-set arrangement of the roll. As the roll 27 rotates (counterclockwise in FIG. 2) past corner 35 the direction of advance of the column is altered at least in part, the part of strand 13 in contact with the surface of roll 27 is allowed to escape from that contact and at the same time other parts of the yarn escape past roll 27 through the restricted exit passage without actually contacting roll 27. Consequently, given segments of the strand will have portions which receive a transferred substance from the roll surface and other portions that did not receive this substance. As roll 27 rotates, it in turn drives transfer roll 28 by contact causing the latter to pickup and transfer additional liquid to roll 27;

Desirably the faceplate 17 of the crimping chamber is slidable vertically in clamps 37, 38 to change the sine and contour of the restricted passage between corner 35 and roll 27 and consequently to vary the pressure on the strand 13 where it contacts roll 27. If this plate 17 is moved downward the pressure of strand 13 against roll 27 will increase and longer spots on strand 13 will receive the liquid, whereas if face plate 17 is raised, shorter spots on the strand will receive the liquid. The transfer action can also be varied by raising or lowering the applicator on the rail portion 2-1 of back plate 14 as heretofore described. Generally, raising the applicator will produce effect similar itO lowering face plate 17.

A method of dyeing and crimping a thermoplastic yarn may also be practiced using the apparatus disclosed. In that method a thermoplastic yarn, such as nylon, is treated and font 1% contains a solution of dye. After the yarn is crimped and spot dyed, the yarn is heated to a suitable temperature, as by drying or steaming, to set simultaneously the crimp in the thermoplastic yarn and the dye on the thermoplastic yarn.

Working Examples The following specific examples will further illustrate the invention. In all examplesthe crimping chamber 18 has a face plate to back plate dimension of 7 inch and a side plate to side plate dimension of /8 inch. Roll 27 was in diameter and positioned as shown in FIGS. 2 and 3.

Example A was processed with edge 35 in the same horizonal plane as the lower edges of the back plate and the two side plates, and Example B was processed with edge 35 spaced A3 inch above this plane. Both examples were processed by introducing yarn into the crimping chamber at the rate of 300 yards per minute.

Specimen A and Specimen B [Yarn--Size 1.34/spun (15 denier 3 staple, bright IRC nylon) with 4.0 t.p.i. Z]

Dye composition: Parts by wt., percent Analysis of One Representative 10 Long Segment of Yarn Number of spots in segment 86 49 Average length of spot in segment (total length of spots in ten feet; divided by number of spots in ten feet) iiiohes 0.21 0.20 Maximum distance between spots in segment inches" 4. 57 7. 52 Minimum distance between spots in segment 7 inches- 0.08 0. 16 Maximum length of spot in segment do 0.63 a 0. 55 Minimum length of spot in segment do- 0. 04 O. 04

The figures given in the foregoing table following the heading Analysis of a Representative 10 Segment of Yarn are intended only to illustrate one specific efiect produced using the process and apparatus. A single ten foot segment from each specimen was selected at random, and these segments are analyzed in the table.

Examples A and B, in which the yarns were thermoplastic yarns, were placed in an autoclave after treatment and steamed at 265 F. for 31 minutes to heat set the crimped thermoplastic fiber and to set the dye.

Various thermoplastic fibers can be used in a combined crimping process. For example disperse dyes can be used to treat yarns made of acetate rayon fibers, and in that case a setting temperature of 230 F. would be used.

It will be apparent from the foregoing description that various substances other than dyes can be applied to strands using the method and apparatus of this invention. For example, in place of a dye, a resist could be applied to a yarn in randomly spaced spots and the yarn subsequently overdyed. Thus a yarn of the type used in specimens A and B could be processed with a solubilized, sulfur-containing, phenol condensates type resist in font 19. The yarn after this treatment could be dyed with brown metallized dyes of the acid class applied in a neutral bath under the normal dyeing conditions for that dye class. The spots where the resist was applied would be white or tan, and the'remainder of the yarn would be brown.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. A method of applying a substance to a strand which comprises i providing a strand that has been bent on itself and packed in a column several times the strands thickness, advancing said column in the direction of its length and toward a memberhaving a surface carrying the substance to be applied to the strand, contacting such surface successively with spaced segments of the strand while under pressure in said column l and thereafter allowing said segments to escape from contact with such surface, allowing the portions of the advancing strand intervening between said spaced segments to advance past said surface out of contact therewith, and continuing to-so advance succeeding segments of said strand. 2. A method of applying a substance to a yarn which comprises providing a yarn that has been bent on itself and packed in a column several times the yarns thickness, 7 advancing said column in the direction of its length and toward a. member having a rotatable surface carrying the substance to be applied'to the yarn, contacting such surface successively with spacedsegments of the yarn while under pressure in said column and thereafter allowing said segments to escape from contact with such surface as it rotates, allowing the portions of the advancing yarn intervening between said spaced segments to advance past said surface out of contact therewith as it rotates, and continuing to so advance succeeding segments of said yarn. 3. A method of spot-dyeing yarn which comprises providing a yarn that has been bent on itself and packed in a column several times the yarns thickness, advancing said'column in the direction of its length and toward a rotatable generally cylindrical roll carrying the dye on its outer surface, contacting such surface successively with spaced segments of the yarn while under pressure in said column and thereafter allowing said segments to escape from contact with such surface as the roll rotates, allowing the portions of the advancing yarn intervening between said spaced segments to advance past said surface out of contact therewith as the roll rotates, and continuing to so advance succeeding segments of said yarn. 4. A method of spot-dyeing yarn which comprises continuously bending a thermoplastic yarn upon itself and packing it in a column several times the yarns thickness,

advancing said column in the direction of its length and toward a rotatable generally cylindrical roll carrying the dye on its outer surface,

contacting such surface successively with spaced segments of the yarn while under pressure in said column and thereafter allowing said segments to escape from contact with such surface as the roll rotates,

allowing the portions of the advancing yarn intervening between said spaced segments to advance past said surface out of contact therewith as the roll rotates,

and continuing to so advance succeeding segments of said yarn.

5. A method in accordance with claim 4 including the step of contacting such dye carrying surface successively with spaced segments of the yarn while under pressure in said column and thereafter allowing said segments to escape from contact with such surface as the roll rotates,

allowing the portions of the advancing yarn intervening between said spaced segments to advance past said surface out of contact therewith as the roll rotates,

and continuing to so advance succeeding segments of said yarn. 7. A method of spot-dyeing yarn which comprises continuously bending a yarn upon itself and packing it in a column in an elongated crimping chamber, advancingsaid column in the direction of its length through said crimping chamber and toward a rotatable generally cylindrical roll partially blocking the exit from said chamber,

applying dye to the outer surface of said roll to be transferred therefrom to said yarn,

contacting such dye carrying surface successively with spaced segments of the yarn while under pressure in said column,

altering the direction of yarn advance and allowing said segments to escape from contact with such surface as the roll rotates,

allowing portions of the advancing yarn intervening between said spaced segments to advance past said surface on said altered course out of contact with the surface as the roll rotates,

and continuing to so advance succeeding segments of said yarn.

8. Apparatus for applying a substance to a strand which comprises a member having a surface carrying said substance,

means for advancing a strand toward said member into contact with said surface while said strand is bent on itself and packed in a column several times the strand thickness,

means for maintaining pressure on said strand while it is in contact with said surface,

mean defining in conjunction with said surface an escape passage through which said strand escapes by altering the direction of its advance,

said escape pasage being large enough for portions of the advancing strand to pass therethrough out of contact with said surface.

9. Apparatus for applying a substance to a strand which comprises a member having a rotatable surface carrying such substance,

means for advancing a strand toward said member into contact with said surface while said strand is bent on itself and packed in a column several times the strand thickness,

whereby said surface may be contacted successively with spaced segments of the strand,

means for maintaining pressure onsaid strand while it is in contact with said surface,

means defining in conjunction with said surface an escape passage through which said strand escapes by altering the direction of its advance,

said escape passage being large enough for the portions of said strand which intervened between said spaced segments to pass through the passage out of contact with said surface.

10. Apparatus for applying a liquid to a yarn which comprises an elongated chamber in which the yarn is packed and bent upon itself,

means for advancing said yarn through said chamber in that condition,

a roll positioned at the exit from said chamber arranged to partially block said exit and adapted to carry the liquid on its external surface,

means for contacting said surface with the yarn as it leaves said chamber and for maintaining pressure on said yarn during such contact,

said roll having its axis ofiset with respect to said chamber so the pressure of the yarn thereon causes said roll to rotate.

11. Apparatus inaccordance with claim 10 in which said crimping chamber is defined by members,

at least one of said members being movable to widen and narrow the gap between said member and the surface of said roll, and

said movable member and the surface of said roll defining a restricted passage through which said yarn escapes as the roll rotates,

whereby movement of said movable member adjusts the pressure on said yarn as it passes through said passage.

12. Apparatus for applying a liquid to a yarn which comprises an elongated stutter-box crimping chamber,

rolls for introducing yarn into said chamber to bend the yarn upon itself and to pack it in the chamber in a crimped condition and to force it through the chamber,

a rotatable roll partially blocking the exit from said chamber,

said roll being positioned with its axis offset with respect to said chamber,

whereby said yarn as it leaves said chamber and presses on said roll create a turning moment in said roll about its axis,

and means for applying a liquid to said roll.

13. Apparatus in accordance with claim 12 in which said means for applying liquid includes a font adapted to contain dye,

a transfer roll rotatable in contact with said partially blocking roll and adapted to have a portion immersed in a dye contained in said font.

14. in apparatus for applying liquid to a strand the combination which comprises a member having a rotatable surface carrying such liquid,

means for advancing a strand toward said member into contact .With said surface while said strand is bent on itself and packed in a column several times the strand thickness,

a font adapted to contain the liquid,

a transfer roll rotatable in contact with said member and adapted to have a portion immersed in the liquid contained in the said font,

and a supply tube for said liquid extending downwardly into said font and terminating at a lower end spaced a distance from the bottom of the font equal to the depth desired for the liquid therein.

15. A method of applying a substance to a strand which comprises providing a strand that has been bent on itself,

advancing said strand toward a member having a surface carrying the substance to be applied to the strand,

contacting said surface successively with segments of the strand and thereafter allowing said segments to escape from contact with such surface,

- allowing the portions of the advancing strand intervening between said segments to advance past said surface out of contact therewith,

and continuing to so advance succeeding segments of said strand.

References Cited in the file of this patent UNITED STATES PATENTS eal when, 

8. APPARATUS FOR APPLYING A SUBSTANCE TO A STRAND WHICH COMPRISES A MEMBER HAVING A SURFACE CARRYING SAID SUBSTANCE, MEANS FOR ADVANCING A STRAND TOWARD SAID MEMBER INTO CONTACT WITH SAID SURFACE WHILE SAID STRAND IS BENT ON ITSELF AND PACKED IN A COLUMN SEVERAL TIMES THE STRAND THICKNESS, MEANS FOR MAINTAINING PRESSURE ON SAID STRAND WHILE IT IS IN CONTACT WITH SAID SURFACE, MEANS DEFINING IN CONJUNCTION WITH SAID SURFACE AN ESCAPE PASSAGE THROUGH WHICH SAID STRAND ESCAPES BY ALTERING THE DIRECTION OF ITS ADVANCE, SAID ESCAPE PASAGE BEING LARGE ENOUGH FOR PORTIONS OF THE ADVANCING STRAND TO PASS THERETHROUGH OUT OF CONTACT WITH SAID SURFACE. 